Abstract: A device includes a semiconductor structure with at least one III-P light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure further includes a GaAsxP1?x p-contact layer, wherein x<0.45. A first metal contact is in direct contact with the GaAsxP1?x p-contact layer. A second metal contact is electrically connected to the n-type region. The first and second metal contacts are formed on a same side of the semiconductor structure.

Abstract: A photonic crystal structure is formed in an n-type region of a III-nitride semiconductor structure including an active region sandwiched between an n-type region and a p-type region. A reflector is formed on a surface of the p-type region opposite the active region. In some embodiments, the growth substrate on which the n-type region, active region, and p-type region are grown is removed, in order to facilitate forming the photonic crystal in an n-type region of the device, and to facilitate forming the reflector on a surface of the p-type region underlying the photonic crystal. The photonic crystal and reflector form a resonant cavity, which may allow control of light emitted by the active region.

Abstract: In an LCD, a backlight having red, green, and blue LEDs is controlled to generate monochromatic light (e,g., blue) during a portion of a cycle, such as an image frame cycle. During another portion of the cycle, all the LEDs are illuminated to create white light. The color filter in the LCD panel contains, for each white pixel, a first color (e.g., red) subpixel filter, a second color (e.g., green) subpixel filter, and a clear subpixel area for passing white light and the monochromatic. The liquid crystal layer shutters are controlled to pass from 0-100% of the light for their associated subpixels to create a color image. With proper control of the shutters, any desired color of each white pixel can be achieved during the cycle. By converting one color filter to a clear area, the transmission efficiency of the display is greatly increased.

Abstract: A semiconductor light emitting device is provided with a separately fabricated wavelength converting element. The wavelength converting element, of e.g., phosphor and glass, is produced in a sheet that is separated into individual wavelength converting elements, which are bonded to light emitting devices. The wavelength converting elements may be grouped and stored according to their wavelength converting properties. The wavelength converting elements may be selectively matched with a semiconductor light emitting device, to produce a desired mixture of primary and secondary light.

Abstract: The present invention relates to a semiconductor device in which energy band gap can be reversibly varied. An idea of the present invention is to provide a device, which is based on a semiconducting material (306) in mechanical contact with a material that exhibits a reversible volume change when properly addressed, e.g. a phase change material (307). The device can, for example, be implemented in light emitting, switching and memory in applications. The semiconducting material can be reversibly strained by applying a local volume expansion to the phase change material. The resulting band gap variation of the semiconducting material can be utilized to tune the color of the light emitted from e.g. an LED or a laser. In other fields of application, contact resistance in semiconductor junctions can be controlled, and this feature is highly advantageous in memories and switches.

Abstract: To increase the lattice constant of AlInGaP LED layers to greater than the lattice constant of GaAs for reduced temperature sensitivity, an engineered growth layer is formed over a substrate, where the growth layer has a lattice constant equal to or approximately equal to that of the desired AlInGaP layers. In one embodiment, a graded InGaAs or InGaP layer is grown over a GaAs substrate. The amount of indium is increased during growth of the layer such that the final lattice constant is equal to that of the desired AlInGaP active layer. In another embodiment, a very thin InGaP, InGaAs, or AlInGaP layer is grown on a GaAs substrate, where the InGaP, InGaAs, or AlInGaP layer is strained (compressed). The InGaP, InGaAs, or AlInGaP thin layer is then delaminated from the GaAs and relaxed, causing the lattice constant of the thin layer to increase to the lattice constant of the desired overlying AlInGaP LED layers. The LED layers are then grown over the thin InGaP, InGaAs, or AlInGaP layer.

Abstract: In a III-nitride light emitting device, the device layers including the light emitting layer are grown over a template designed to reduce strain in the device, in particular in the light emitting layer. Reducing the strain in the light emitting device may improve the performance of the device. The template may expand the lattice constant in the light emitting layer over the range of lattice constants available from conventional growth templates. Strain is defined as follows: a given layer has a bulk lattice constant abulk corresponding to a lattice constant of a free standing material of a same composition as that layer and an in-plane lattice constant ain-plane corresponding to a lattice constant of that layer as grown in the structure. The amount of strain in a layer is |(ain-plane?abulk)|/abulk. In some embodiments, the strain in the light emitting layer is less than 1%.

Abstract: A semiconductor light emitting device includes an active region, an n-type region, and a p-type region comprising a portion that extends into the active region. The active region may include multiple quantum wells separated by barrier layers, and the p-type extension penetrates at least one of the quantum well layers. The extensions of the p-type region into the active region may provide uniform filling of carriers in the individual quantum wells of the active region by providing direct current paths into individual quantum wells. Such uniform filling may improve the operating efficiency at high current density by reducing the carrier density in the quantum wells closest to the bulk p-type region, thereby reducing the number of carriers lost to nonradiative recombination.

Abstract: A system for purifying a fluid uses ultra violet (UV) light to inactivate micro-organisms present in the fluid. The system has an arrangement of UV light emitters on perforated plates. The fluid, while passing through perforations in the perforated plates, is exposed to the UV light emitted by the UV light emitters. Micro-organisms present in the fluid pass very close to the UV light emitters. The UV light absorbed by the micro-organisms causes genetic damage and inactivation. The system has feedback units providing feedback about the physical properties of the fluid to a power unit supplying power to the UV light emitters. The power unit varies the amount of power supplied to the UV light emitters, based on the feedback.

Abstract: A ceramic body comprising a wavelength converting material is disposed in the path of light emitted by the light emitting region of a semiconductor structure comprising a light emitting region disposed between an n-type region and a p-type region. A layer of transparent material is also disposed in the path of light emitted by the light emitting region. The transparent material may connect the ceramic body to the semiconductor structure. Particles configured to scatter light emitted by the light emitting region are disposed in the layer of adhesive material. In some embodiments the particles are phosphor; in some embodiments the particles are not a wavelength-converting material.